fun main(args: Array<String>) {
    println("Hello World!")

    // Try adding program arguments via Run/Debug configuration.
    // Learn more about running applications: https://www.jetbrains.com/help/idea/running-applications.html.
    println("Program arguments: ${args.joinToString()}")
    val popcorn = 5//只读变量
    var customer = 10;//可变变量
    customer = 8
    println(customer)
    println(popcorn)
}